Nghiên cứu hệ thống lái steer by wire điện tử thủy lực TT TIENG ANH

 Objects, scope of the research: This is theoretical research and experimental research to convert hydraulic power steering system to electro - hydraulic SBW system on HINO 300 Series

MINISTRY OF EDUCATION AND TRAINING

UNIVERSITY OF TRANSPORT AND COMMUNICATIONS

NGUYEN XUAN TUAN

RESEARCH ON ELECTRO – HYDRAULIC STEER

This thesis is completed at:

University Of Transport And Communications

Scientific Advisers:

1 Associate Prof Dr Nguyen Van Bang

2 Associate Prof Dr Đinh Thi Thanh Huyen

INTRODUCTION

 The urgency of the research

Steer-by-wire (SBW) system is one of the systems that apply electronic technology Recently, many scientists in the country and around the world have been studying this system

This modern technology is forecasted to be used on vehicles in big cities in the future Therefore, studying the SBW system has scientific and practical significance in order to grasp advanced technologies in the world

 Objects, scope of the research:

This is theoretical research and experimental research to convert hydraulic power steering system to electro - hydraulic SBW system on HINO 300 Series trucks

 Scientific significance of the study:

- Completing the conversion of hydraulic power steering to electro

- hydraulic SBW systems on HINO 300 Series truck vehicle

- Building a dynamic and a simulation model of the electro - hydraulic SBW system which is suitable for the research object, achieving the required accuracy

- Researching appropriate control methods, building control laws Design and manufacture an industrial controller that works stably on the research object

 Practical significance of the study:

- The electro - hydraulic SBW system mounted on the HINO 300 Series is an industrial product that has been tested in many operating modes

- Research results can be used for teaching, scientific research, technology transfer

- Opening a new research direction on the conversion from normal car steering system to SBW system

CHAPTER 1 OVERVIEW OF THE RESEARCH

1.1 Steering system with rotation and directional stability

In some cases, it is safer to use the steering system instead of the brakes because steering creates less friction between the tires and the road When the rear tire has reached the limit of grip, the only controller

is the front wheel, if braking in this situation often leads to the vehicle losing direction and spinning uncontrollably[13], [15]

1.2 Steer by wire system

1.2.1 Technical specifications of SBW system

SBW systems have been studied at present from Figure 1.9 to Figure 1.11:

Fig 1.9: Steer by wire - 3 electric motors

Fig 1.10: Steer by wire - 1 electric motors

Fig 1.11: Steer by wire - Hydraulic assist

1.2.2 Conversion from normal steering system to SBW system

Instead of using a mechanical steering shaft to drive the steering mechanism, the SBW system uses a steering actuator consisting of 1 motor to create the feeling, 1 motor to rotate the steering mechanism and the steering gear Electronic control as shown in Figure 1.12

Fig 1.12: Conversion from conventional system

1.3 Research in the country and in the world

1.3.1 Research in the country:

- Research of Author Tran Van Loi [1]÷[6]

- Research of Author Nguyen Ba Hai [20]

1.3.2 Research in the world:

 Research on model and dynamics of steer by wire system:

Author Sheikh Muhammad Hafiz fahami1 [21] Author Paul Yih,

J Christian Gerdes [22]; Author's research Eid S Mohamed, Saeed A Albatlan [23]

 Research on control:

Author Paul Yih [13]; Author A dem Kader (SBW) [24]; Author Jack J Kenned, Professor V.R Patil [25]; Author Chunyan Wang, Dong Zhou, Wanzhong Zhao, Xiaoyue Gu [26]; Author Salem Haggag, David Alstrom, Sabri Cetinkunt, and Alex Egelja [27]; Author Yixin Yao [28]; Author Se-Wook Oh, Ho - chol CHAE, Seok – Chan YUN [29]; Author Swinburne University, Melbourne, Úc [30]; Author Sheikh Muhamad Hafiz [21]

 Research on feedback:

Author Se Wook Oh [29]; Author F.Bolourchi [32]; Author Ba-Hai Nguyen, Jee-Hwan Ryu [20]; Author Emad Mehdizadeh, Mansour Kabganian, and Reza Kazemi [34]; Author Andrew Liu và Stacey Chang[35]; Author Paul Jih [13]

1.4 Objectives, content and research methods:

1.4.1 Research Objectives

Research on converting the normal steering system with hydraulic assistance to the electro - hydraulic SBW system on truck vehicles

1.4.2 Research content

The thesis has 04 chapters:

- Chapter 1 Overview of the research

- Chapter 2 Building a hydraulic model and a simulation model of the electro - hydraulic SBW system

- Chapter 3 Design of controller for electro - hydraulic SBW system

- Chapter 4 Experimental research on HINO 300 Series

- The research method and content of the thesis have been identified

CHAPTER 2 BUILDING DYNAMICS AND SIMULINK MODEL OF THE ELECTRO – HYDRAULIC SBW SYSTEM 2.1 Theoretical basis

The SBW system is a mechanical system with many degrees of freedom and complex linkage, in dynamical models often include elements with mass and connections To build a mathematical model, the thesis uses Lagrange equations of type 2, Dalambe's principle Then the equation of motion will be established on the basis of taking the sum of the moments and forces acting on the mechanical system [7]

2.2 Building dynamics model

2.2.1 Assumptions

The joints of the mechanical model have mass at the center of gravity; The stiffness and drag coefficient are constant; The speed of the car is constant; Steering wheel rotation speed is constant; Treat the hydraulic system as adiabatic and isothermal; The flow rate coefficient is constant; The output pressure of the hydraulic pump is constant; power

system with stable source voltage; The stator's flux remains unchanged; The torque coefficient and the electromotive force of the motor remain unchanged

Fig 2.4: Dynamic model of electro - hydraulic SBW system

The physical relationship between the sub-models in the electro - hydraulic SBW steering system is presented in Figure 2.5

Fig 2.5: Diagram of the physical relationship between the sub-models in

the electro-hydraulic SBW system

2.2.2 Hydraulic power steering system

The hydraulic power steering system is modeled as Figure 2.6[36]÷[39]

Fig 2.6 Dynamic model of hydraulic system

2.2.3 DC motor

Model of armature of DC motor as shown in Figure 2.7

Fig 2.7: Model of armature of DC motor

Equation (2.36) of the electric motor:

𝐽𝑚𝜃̈𝑚(𝑡) + (𝐵𝑚+ 𝐾𝑏𝐾𝑚/𝑅)𝜃̇𝑚(𝑡)

= (𝐾𝑚/𝑅)𝑉(𝑡) − 𝜏𝑙(𝑡)/𝑖𝑚

(2.36)

2.2.4 Front wheel driver

The drag moment is related to the wheel alignment angles with

the road surface, as shown in Figure 2.8[34], is determined by the formula

(2.40):

Fig 2.8: Guide wheel assembly model

𝑇𝐹_𝐺 = (𝑡𝑝+ 𝑟 𝑡𝑎𝑛𝑣)𝑐𝑜𝑠√𝜆2+ 𝑣2𝐹𝑦𝑓+ 𝑑 𝑠𝑖𝑛𝜆 𝑠𝑖𝑛𝛿 𝐹𝑧𝑓 (2.40)

2.2.5 Steering wheel

The dynamic model of the steering wheel is shown in Figure 2.9 The

differential equation is represented by (2.41) and (2.42)

Fig 2.9: Dynamic model of the steering wheel

𝐽𝑠𝑤𝜃̈𝑠𝑤= −𝐵𝑠𝑤𝜃̇𝑠𝑤− 𝐶𝑠𝑤(𝜃̇𝑠𝑤−𝜃̇𝑚1

𝑖𝑚1) − 𝐾𝑠𝑤(𝜃𝑠𝑤−

𝜃 𝑚1

𝑖𝑚1)+ 𝑇 𝑠𝑤 − 𝑇 𝐹−𝑆𝑊 + 𝑇 𝑐1

Steering actuator dynamic model is shown in Figure 2.10 [36]

The differential equation is represented by (2.43) ÷ (2.54)

Fig 2.10: Steering actuator dynamic model

𝑅 2

𝑉 𝑚2 (𝑡)−𝑇𝐹𝑅𝑚2−𝑇𝑐2

𝑖 𝑚2

(2.43)

2.2.7 Dynamic model of changing direction of car motion

Consider the motion model of the car in the road plane as shown

in Figure 2.11 [34] with 𝑣𝑥= 𝑥̇ = 𝑐𝑜𝑛𝑠𝑡, The differential equation is

represented by (2.58) and (2.59)

Fig 2.11: Dynamic model for changing direction of car motion

Electronic control unit for electro - hydraulic SBW system

includes: Angle sensors, motor control circuit DCM1, DCM2, electronic

controller SBW, electric motor DCM1, DCM2

2.3 Building simulation block diagram

2.3.1 Simulation block diagram of the steering wheel dynamics

Block diagram simulation of the steering wheel dynamics is

shown in Figure 2.12, built using matlab/Simulink software

Fig 2.12: Simulation dynamic of steering wheel dynamic

2.3.2 Simulation block diagram of the steering actuator dynamics

Block diagram simulation of the steering actuator dynamics is

shown in Figure 2.13, built using matlab/Simulink software

Fig 2.13: Simulation dynamic of Steering actuator dynamic

2.4 Conclusion

- Built a dynamic model for the electro-hydraulic SBW system, in

which there are sub-models: Hydraulic power steering system, DC motor,

guide wheel, steering wheel, Steering actuator, model changing direction

of car movement

- Built a block diagram to simulate the dynamics of the steering

wheel and the actuator using Matlab/Simulink software

CHAPTER 3 CONTROLLER DESIGN FOR ELECTRO –

HYDRAULIC SBW SYSTEM 3.1 Slide mod control (SMC) overview

 Design steps slide mod controller orbit tracking:

- Step 1: Represent the I/O relationship of the nonlinear object:

(3.4)

Inside K>0 The larger K is the faster σ → 0

- Step 4: Design a low-pass filter of the input signal to ensure that

the differentiable 𝑦𝑑(𝑡) calibration signal is suppressed to the nth order

3.2 Controller design for electro - hydraulic SBW system by SMC

3.2.1 Controller design for Steering actuator

 Represent the I/O relationship of the nonlinear object: 𝑥̇ = 𝐴𝑥 +

3.2.2 Controller design for Steering wheel

 Represent the I/O relationship of the nonlinear object:

3.3 Simulation of electro - hydraulic SBW system

3.3.1 Simulation block diagram of electro - hydraulic SBW system

Figure 3.10 shows the simulation block diagram of SBW system

using Matlab/Simulink software

Fig 3.10: Block diagram simulation of SBW system

3.3.2 Simulation of the steering wheel

Simulation results: Figure 3.11 show the steering wheel angle 𝜃𝑠𝑤; Figure

3.12 show the steering wheel angle DCM1 simulation 𝜃𝑚1 and desire

𝜃𝑚1𝑑 ; Figure 3.13 show the error 𝑒1 DCM1 simulation and desire angle:

𝑒1𝑚𝑎𝑥= 0.1682 (rad), RMS 𝑒1= 0.098 (rad); Figure 3.14 show control voltage DCM1: RMS = 5,7225 (V), max = 9,8(V)

Fig 3.11: Graph showing steering wheel angle

Fig 3.12: Graph showing DCM1 simulation and desire angle

Fig 3.13: error 𝑒1 simulation and desire angle

Fig 3.14: Graph showing DCM1 control voltage

3.3.3 Simulation of the steering actuator

Simulation results: Figure 3.15 show the simulation angle 𝜃𝑚2 and desire

𝜃𝑚2𝑑 ; Figure 3.16 show error 𝑒2: 𝑒2𝑚𝑎𝑥=0,0273 (rad), RMS𝑒2 = 0,0105 (rad); Figure 3.17 show simulation angle 𝜃𝐹𝑊 and desire 𝜃𝐹𝑊𝑑 ; Figure 3.18 show error 𝑒3: 𝑒3𝑚𝑎𝑥= 0.009 (rad), RMS𝑒3 = 0.0053 (rad); Figure 3.19 show DCM2 control voltage: max = 9,8 (V), RMS = 5,7225 (V); Figure 3.20 show hydraulic power 𝐹𝐵: RMS/max = 401,88/ 807,47 (N);

Fig 3.15: Graph showing the simulation angle and deside

Fig 3.16: Graph showing error 𝑒2

Fig 3 17: Graph showing simulation angle and deside angle

Fig 3.18: Graph showing error 𝑒3

Fig 3.19: Graph showing DCM2 control voltage

Fig 3.20: Graph showing hydraulic power 𝐹𝐵

3.3.4 Simulation of changing direction of car movement

Figure 3.21 show steering wheel angle; Figure 3.22 shows the simulated horizontal body displacement at three speeds 5m/s, 10 m/s, 15 m/s; Figure 3.23 shows the simulated body rotation angle at three speeds 5m/s, 10 m/s, 15 m/s; Figure 3.24 shows the drag torque of the steering system

Fig 3.21: Graph showing steering wheel angle

Fig 3.22: Graph showing horizontal body displacement

Fig 3.23: Graph showing body rotation angle

Fig 3.24: Graph showing the drag torque

Simulation at max speed: Vmax = 30,5 m/s (109 km/h):

Fig 3.25: Graph showing horizontal body displacement

Fig 3.26: Graph showing body rotation angle

Fig 3.27: Graph showing the drag torque

CHAPTER 4 EXPERIMENTAL RESEARCH

4.1 Research purpose and methods

 The purpose of the experiment on cars HINO 300 Series with hydraulic power steering: Measure, evaluate parameters and determine the angular transmission ratio of the steering system

 Purpose of experiment on car HINO 300 Series with electro - hydraulic SBW system:

- Evaluate the stable and reliable operation of the electro - hydraulic SBW system designed on the HINO 300 Series in static modes, operating on traffic roads, turning around with the smallest turning radius - Provide

input data for the theoretical model for testing, the theoretical model for the electro - hydraulic SBW steering system

 Directly tested on HINO 300 Series cars in static modes, operating

on internal roads, turning around with the smallest turning radius

4.2 Experimental study with hydraulic power steering system 4.2.1 Preparation steps

 The test truck vehicle is a HINO 300 Series

 Experimental equipment and tools: Angle measuring device for guiding wheel; Steering wheel dirt gauge

Fig 4.7: Relation of steering wheel and wheel guide angle

Fig 4.8: Relation of steering wheel and wheel guide angle

Fig 4.10 show relation angle , and :

Fig 4.10: Relation angle , and 

0 10 20 30 40

10 20 30 40

0 10 20 30

 The gear ratio of the steering system is according to the following formula:

2

24.7

vl htl

 



4.3 Electro-hydraulic SBW system conversion

4.3.1 Survey, measure parameters on trucks HINO 300 Series

The process of surveying and measuring the parameters of the steering system and surveying to plan the conversion of the steering system on the HINO 300 Series was carried out at HINO Vietnam and the University of Transport

4.3.2 Steering wheel conversion

Figure 4.13 show steering wheel after making

Fig 4.13: Show steering wheel

4.3.3 Steering actuator conversion

Figure 4.15 show steering actuator after making

Fig 4.15: Steering actuator

4.3.4 Calculation and testing of working parameters of SBW

electro - hydraulic system on HINO 300 Series truck cars

 Electro - hydraulic SBW steering gear ratio

4.3.5 Design of the controller for the electro – hydraulic SBW

system

Control diagram of the system as shown in Figure 4.18

Fig 4.18: Control diagram of the system

4.3.6 Results display and data storage

Electro - hydraulic SBW system controller with computer to display and store results

4.4 Experiment with electro - hydraulic SBW system

4.4.1 Preparation steps

 Experimental truck vehicle:

HINO 300 Series truck vehicle with electro - hydraulic SBW system

 Experimental location: Using internal roads in the University of Transport for experimentation

 Experimental equipment: GPS device and decoder placed in the car connected to the computer via USB port

4.4.2 Experimental results

 Experiment in steady state:

- Without power hydraulic: Figure 4.55 show steering actuator angle

𝜃𝑚2𝑡𝑛

𝑖𝑚2 and steering wheel angle 𝜃swtn; Figure 4.56 show error 𝑒4: RMS 𝑒4= 0,0978 (rad), 𝑒4𝑚𝑎𝑥 = 0,15 (rad); Figure 4.57 show DCM2 control voltage 𝑉m2tn max = 10 (V)

Fig 4.55: Graph showing the steering actuator and steering wheel angle

Fig 4.56: Graph showing the error 𝑒4

Fig 4.57: Graph showing the DCM2 control vontage

- With power hydraulic: Figure 4.59 show steering actuator angle

𝜃𝑚2𝑡𝑛

𝑖𝑚2 and steering wheel angle 𝜃swtn; Figure 4.60 show error 𝑒4: RMS

𝑒4= 0,1 (rad), 𝑒4𝑚𝑎𝑥 = 0,17 (rad); Figure 4.61 show DCM2 control voltage

Fig 4.59: Graph showing the steering actuator and steering wheel angle

Fig 4.60: Graph showing the error 𝑒4

Fig 4.61: Graph showing the DCM2 control vontage